The present invention relates to an electronic cash register which prints character patterns such as sales data, trade names of sales goods and the like on a receipt and issues the receipt.
Recently, electronic cash registers have come into being which use a dot printer which can print formal character patterns of sales data on a receipt and also can print commercial characters, trade names, department names, and the like of which the contents can be changed on the receipt. In such electronic cash registers a read only memory (ROM), having character dot pattern memory areas for storing a plurality of character pattern data, each of which is represented by a dot matrix, and their character codes is used. In the case of printing characters such as messages or the like on a receipt by operating keys of a predetermined combination of numeral keys, department keys and function keys on the keyboard for every character using the character codes corresponding to these message characters, the message data is stored in the print memory area in a random access memory (RAM). This message data is read out upon sales registration of goods and is printed together with the sales data on a receipt by a dot printer.
The message data is ordinarily indicated by alphabets, numerals and the like. However, the amount of character patterns which can be stored in the dot pattern memory area in the RAM is limited, so it is difficult to store all of the necessary character data in this dot pattern memory area. For instance, it is impossible to print special characters such as, e.g., Grecian characters or the like other than alphanumeric characters which are ordinarily used in everyday business transactions. In word processors or the like, characters which are not registered can be generally registered by sequentially writing therein, for example, dot data "1" at the position designated by the cursor while watching the display screen. However, in ordinary electronic cash registers, a display having a display screen of (a plurality of columns) .times.(a plurality of dots) is not used; therefore, it is generally considered to be impossible to register new special letters by manually operating keys.